Pamidronate in preoperative and long-term treatment of hypercalcemia in 13 patients with primary hyperparathyroidism.

The definitive treatment of primary hyperparathyroidism (pHPT) is surgical. However, medical approches should be attempted in some patients, such as the elderly or in those patients with severe cardio-pulmonary disease. Biphosphonates are an important class of osteotropic drugs. Disodium pamidronate (pamidronate APD) is effective in various conditions including Pagetʹs disease, tumor-induced hypercalcemia, osteolitic bone metastases. We investigated the effects of APD on serum and urinary markers of bone formation in 13 patients with primary hyperparathyroidism. In 9 patients APD (30-90 mg) was intravenously administered from twenty to ten days before parathyroidectomy for the medical treatment of hypercalcemia. Until now the other 4 patients have not been submitted to parathyroidectomy because of different reasons. In all the cases 30 mg of APD were dissolved in 500 ml of saline and they were infused in 4 hours during the morning. Serum calcium decreased one day after APD administration in all the examinated cases. Serum calcium decreased in the normal range in 8 cases (the lowest value of calcium after APD was 9,6 to 11,24 mg/d). The plasma calcium fall was accompained by a rise in the parathyroid hormone levels in 12 of 13 patients and it lightly decreased in the other one (113 versus 98,1 pg/ml). In 8 cases we measured urinary pyridinoline and deoxipyridinoline: these markers of osteoclastic activity decreased over a 15-day period after pamidronate infusion. In the 4 patients not surgically treated APD was performed for several months and 60-120 mg of the drug led to a significant and long-lasting decrease of serum calcium levels (4-7 months without specific therapy). In conclusion APD is a safe and effective mean of lowering plasma calcium in primary hyperparathyroidism. APD can be used for the preoperative management of hypercalcemia in pHPT, in mild primary hyperparathyroidism and in aged and fragile patients where it can be tried as an alternative to surgery